Compressible electrical connecters



, United States Patent [72] Inventors John A.Toedtman [50] FleldofSeerchl74/7l,72,

so. 1.61116; 84.1, 90, 94; 339/276; 287/109; 29/628, 630(F) Francis E.Stephens, Webster Groves, m [56] References Cited 21 Appl. N0. 807,281UNITED STATES PATENTS 1 Files! Mmh 14, 1969 2,884,478 4/1959 Becker 6!al 174/94 1 Patented Dec-8,1970 3,134,844 5/1964 Myers 174/94 AssamIntern-"ml TelenhomkTeksrarh 3,235,654 2/1966 Bldridge,Jr... 174/94 pration 3,236,938 2/1966 Toedtman..... 174/94 New York/New Yerk 3,275,7389/1966 Flynn e161. 174/94 a corporation of Delaware 52] US. Cl.

I 74/7] [51 1 Int. Cl. H023 15/08 Primary Examiner- Darrell L. ClayAtromeys--C. Cornell Remsen, Jr., Walter J. Baum, Percy'P. Lantzy, J.Warren Whitesel, Delbert P. Warner and James B. Raden ABSTRACT:Compressible electrical connectors have integral enclosure tabs whichlock in place and provide electrically and mechanically secure joints.

PATFNTEUUEB-8l970 3.646366 SHEET 1 OF 2 IN VE/VTOR JOHN Q, 7060 TMKMpm/as E, am /mm ATTORNEY COMFRIESSIBLE ELECTRICAL CONNECTORS Thisinvention relates to new and improved electrical connectors. Moreparticularly, it relates to compressible connectors for large diameterconductors.

Connectors of the described type are generalalthough not always-used onelectrical conductors in the power distribution industry. Generally, adesigner of these devices faces several problems. The connectors must beadaptable for connecting a range of differing diameter and shapedconductors. Additionally, the connector should be of a construction suchthat, when the connector is compressed around the surface of theconductor, the conductor is tightly sealed so as to prevent entry offoreign elements and contaminants, such as moisture and the like. Oncethe connector is sealed, it must stay sealed. For example, the connectorshould be of a construction such that when pressure is applied at pointsalong the body of the connector to seal it tightly, this local squeezingor crimping does not cause an adjacent section of the connector whichhas already been scaled to pop open. Moreover, if the conductor cablesare wound in a helical configuration, the connector must be constructedso that it will not be forced open if the cables exert an inherentoutward pressure resulting from the helical memory.

An object of this invention is to provide compressibleeleo tricalconnectors having an integral enclosure tab which locks in place andprovides an electrically and mechanically secure joint.

Another object is to provide connectors which can be sealed tightly withgood contact pressure on the conductor and which will not pop open at apreviously sealed point when pressure is exerted at an adjacent point toseal the connector.

Still another object is to provide connectors which will resist internalpressures exerted by the conductors and will retain their lockedcondition after they are sealed.

An additional object is to provide connectors for a wide variety oflarge diameter conductors.

in keeping with one aspect of the invention, these and other objects areaccomplished by a connector having a substantiallyI-I-shaped crosssection with two pairs of arms spaced to provide a recess adapted toreceive a conductor. One of the arms of each pair includes an integralenclosure tab. The inventive connector includes means for establishingmechanical interference between the enclosure tab and the oppositelydisposed, overlapping arm when the connector is in a closed andcompressed state enfolding and gripping and conductor disposed in thebody recess. Thus, the enclosure tab locks in place, providing anelectrically and mechanically secure joint.

More particularly, the mechanical interference between the tab and thearm may be established by a variety of means such as interlocking ridgesr serrations on the inside of the arm and on the tab surface. Or, oncompression of the connector, an interference fit may occur responsiveto a cold flow of metal from a smooth tab surface into a ridged orserrated surface on the inside of the arm and vice versa. Aninterlocking cam like surface on the inside of the arm may lock intoteeth on the tab surface and vice versa, and the like. It is by virtueof this mechanical interference that the connector overcomes anypropensity to pop open when pressure is applied at adjacent points alongthe axis of the connector to seal it or as a result of internal pressurecreated by the inherent mechanical characteristics of the particularconductor being sealed.

The integral enclosure tabs which are affixed to the arms of the bodyare easily bendable over the recesses formed in the body of theconnector to hold the conductors. The tabs are pivoted over theirassociated recesses by a hinging action occuring at the inside interfaceof each tab and the arm to which the tab is affixed in order to provideexact and uniform alignment oi. the tab so that it interlocks properlywith the corresponding, oppositely disposed arm.

The above mentioned and other features and objects of this inventionwill be best understood by reference to the following description of anembodiment of the invention taken in conjunction with the accompanyingdrawings in whichz FIG. 1 is a perspective view of the connector beforecompression;

FIG. 2 is an end elevational view of the connector before compression;

FIG. 3 is an end elevational view of the connector illustrating theaction of the compression tool in bending the tabs inwardly of theirassociated recesses and the oppositely disposed arms and, also,illustrating the hinging action at the interface of the tab and the armto which it is affixed;

FIG. 4 is an end elevational view of the connector body fully compressedwith the tabs locked into position;

FIG. 5 is a side elevational view of the connector after compression;

FIG. 6 is a perspective view of a second embodiment of the invention;

FIGS. 7A, 7B and 7C (which corresponds to the fragment of FIG. 4 whichis enclosed within a dot-dashed circle 7C) are fragmentary, end viewsillustrating a modified construction of the tab and the mating portionof an arm utilized on the connector; and

FIGS. 8A (which corresponds to the fragment of FIG. 6 which is enclosedby dot-dashed lines 8A), 8B and 8C are fragmentary, end viewsillustrating another modified construction of the tab and the matingportion of an arm utilized on the connector.

An electrical connector is shown in FIG. I and FIG. 2 to illustrate apreferred embodiment exemplifying the principles of the invention. Ingeneral, this embodimentincludes a substantially I-I-shaped body,generally indicated as 11, made ofa malleable metal. The body llincludes two pair of arms 12 and 13 extending outwardly from anintervening partition M. The arms 12 are spaced-apart to provide arecess 15. Similarly, the arms 13 are spaced to provide a correspondingrecess 16, usually of slightly smaller dimensions.

The body 11 is provided with a plurality of longitudinal alternatelyarranged series of deformable ribs 17 and grooves 18. Specifically, theribs I7 extend along the recess between projecting into the recess 15and along the inside surface of each arm 12.

The plurality of deformable ribs 17 and alternately arranged grooves 18provided along the inside surface of each arm 12 and along the recessbottom form a generally arcuate cross' sectional outline. Thisconfiguration of ribs I7 and grooves 18 assures bending of the arm 12 ina desired manner as subsequently described and enables the arms 12 towrap or'enfold the conductor very closely.

The body I1 is provided with a plurality of alternating deformable ribs21 and grooves 22 extending along the bottom of the other recess I6 andalong the inside surface ofeach arm 13. The ribs 21 extend into theinterior of recess l6.

Correspondingly, the ribs 21 and grooves 22 constitute a generallyarcuate cross-sectional configuration. It will be noted that because therecess 16 is slightly smaller to accommodate a smaller conductor, thereare fewer ribs 21 extending along the recess bottom and up the inside ofthe arm 13 than there are along the bottom of the slightly larger recess15 and along arms 12.

The ribs 17 in recess 15 and the ribs 21 in recess 16 constitute ayieldably deformable means under pressure to accommodate the conductorsize and to conform to the configuration of said conductor.

Attached integrally with one of the arms 12 is a camlike tab 23extending beyond the end of the other opposite arm 12. Tab 23 has agenerally arcuate cross-sectional outline on its inside and outsidesurfaces. On the inside surface of tab 23 is a plurality oflongitudinal, alternately arranged series of deformable ribs 28 andgrooves 2%, such ribs 28 deforming under pressure against the conductorto conform to the conductor configuration. At the inside interface ofarm I2 and tab 23 and extending longitudinally the length of theinterface, there is a locking rib or ratchet 24 and a groove 25 toreceive such rib or ratchet.

According to the invention, a means is provided for establishingmechanical interference between tab 23 and the oppositely disposed arm12 when the tab 23 is in a closed and compressed state enfolding andgripping the conductor disposed in the recess 15.

- Ridges or serrations 26 are formed on the outside, top surface ormating edge of tab 23 and extend longitudinally the length of such tabbetween its ends. Corresponding, interlocking ridges or serrations 27are provided on the inside surface or mating portion of the opposed arm12 and extend longitudinally the length of such arm. As will becomeapparent, a conductor is inserted into groove 15 with the tab 23 in theopen position then upon compression as shown in FIG. 3, the groove 25engages the locking rib 24 and the tab 23 is pivoted on thisinterlocking hinge closing over the conductor. This interlocking hingemeans insures proper alignment of tab 23 as it is bent inwardly of itsassociated recess 15 and inwardly of the opposed arm 12 before the arms12 are compressively overlapped and the opposed arm 12 is interlockedwith tab 23 by means of mechanical interference created between theridges or serrations 26 on the mating edge of tab 23 and theinterlocking, complementary ridges or serrations 27 on the matingportion of arm 12. The conductor is, thus, enfolded and locked in placewithin the recess 15.

The length of tab 23, or in other words, the distance of the tab 23extending outwardly from its associated arm 12, is less than the widthof the recess 15 between the arms 12. This structural arrangementassures that the tab 23 will enter the recess 15 when the tab 23 is bentover. Also, upon compression, a mechanical interference is establishedbetween the ridges or serrations 26 on the tab 23 and the complementary,interlocking ridges or serrations 27 on the inside surface of theopposed arm 12.

A similar tab 31 is attached integrally to one of the arms 13 at thesame side of the connector as the other corresponding tab 23. Tab 31extends outwardly beyond the end of the other arm 13. Again, tab 31 hasa generally arcuate cross-sectional outline on its inside and outsidesurfaces and a plurality of iongitudinal, alternately arranged series ofdeformable ribs 36 and grooves 37 are formed on the inside surface.Also, tab 31 is provided with a locking rib or ratchet 32 at itsconnection to its associated arm 13 and there is a groove 33 in theassociated arm 13 to receive such rib or ratchet so that the tab 31 canbe pivoted on this interlocking hinge into a closed position over aconductor inserted laterally into groove 16. As a result of theinterlocking hinging action between the rib 32 and the groove 33, thetab can be easily bent inwardly toward the other arm 13 in properalignment. Ridges or serrations 341 are formed on the outside, topsurface or mating edge of tab 31 and extend the length of the tabbetween its ends. These ridges or serrations 36 are adapted to engagecomplementary, interlocking ridges or serrations provided on the insidesurface or mating portion of the opposite arm 13 when the tab is bentinwardly of the opposite arm 13 and the conductor is enfolded andgripped in the recess 16 under compressive action. Thus, this tab 31 isalso of a slightly lesser length than the width of the recess 16 betweenthe arms 13 to assure that the bendable tab 26 will enter the recess 16.

To install the connector, a conductor 41 is inserted into recess 15 andthe tab 23 is pivoted into position over the conductor 4 1 bycompressive action of a compression tool 42 as shown in FIG. 3. Assuggested above, the tab 23 enters the recess 15 inside of the oppositearm 12 and the mating edgeof tab 23 interlocks with the mating portionof arm 12.

A smaller conductor 43 is disposed in the recess 16 and the tab 31 ispivoted into position over the conductor under pressure as is shown inFIG. 3. Similarly, the tab 31 enters and closes the recess 16 inside ofthe opposite arm 13 by the interlocking action of the mating edge of tab31 and the mating portion of arm 13.

The compression tool 12 may be of any suitable type. The jaws 42a, 121)are fitted over the connector body 11 and manipulated to exert acompressive pressure, thereby squeezing the body 11 to the conditionillustrated in F168. 41 and 5.

Specifically, the action of tool 42 is to engage the tabs 23 and 31 andbend them inwardly of the associated recesses 15 and 16 and inwardly ofthe oppositely disposed arms 12 and 13, respectively. Upon bending oftabs 23 and 31, locking ribs 24 and 32 are engaged by theircorresponding grooves 25 and 33 respectively, in an interlocking,hinging action which causes the tabs 23 and 31 to bend in exactalignment with the oppositely disposed arms 12 and 13. This initialaction of tool 42 and the bending and hinging of tabs 23 and 31 is bestshown in FIG. 3.

Upon continued compressive action of tool 42, the arms 12 and 13 arebent toward each other enough so that the mating edges on tabs 23 and 31and the mating portions on arms 12 and 13 come into contact. Thisprovides interlocking, overlapping connections that enfold and grip theconductors 41 and 43 as is shown in FIG. 4. The tabs 23 and 31 and thearms 12 and 13 are disposed around their associated conductors 41 and 43in close contiguous relation. The tabs 23 and 31 are compressivelyinterlocked with arms 12 and 13 by means of mechanical interferencecreated between the ridges or serrations 26 and 34 on the mating edgesof tabs 23 and 31 and the complementary ridges or serrations 27 and 35on the mating portions of arms 12 and 13 respectively. Thus, theconnector is interlocked in a manner such that crimping at an adjacentpoint along the connector will not cause the seal to pop open. Also, theinternal pressure exerted by the conductor cables will not cause theseal to be forced open.

Upon compression of the connector, the ribs 17 and 28 are deformed andyield under pressure by the conductor 41 to accommodate the particularsize of the conductor 41. As the ribs 17 and 28 are deformed, the ribs17 and 28 wipe the contact surfaces with a cleaning action and yieldablyconform precisely to the conductor configuration to provide an optimumcontact.

As a result of the provision of grooves 18 along the bottom of recess 15and along the inner surfaceof arms 12, the arms 12 bend toward eachother at the bottom of the recess 15 and thereby preclude any bulging inthis area of the recess bottom.

If a compound or paste (not shown) is utilized in the connector, thecompound will be retained in the grooves 18 and 29 by the ribs 17 and28. Moreover, such compound will be forced into the stranding of theconductor 41 for more effective action.

it will be realized that as the ribs 17 and 28 yieldably deform underpressure by the conductor 41 upon compression of the connector, the ribs17 and 28 accommodate the conductor 41 and thereby prevent excessivepressure from developing on the conductor. Of course, it will be readilyapparent that this deformation feature of the ribs 17 and 23 enables theinsertion and effective connection of any conductor 41 within a widerange of sizes.

in a similar manner, the conductor 43 deforms the ribs 21 and 36 underpressure so that the ribs 21 and 36 accommodate the particular size ofthe conductor 43. Again, the ribs 21 and 36 conform to the particularshape and contour of the conductor 43, and particularly the ribs 21 and36 wipe the surface of the conductor 43 with a cleaning action andconform precisely with the conductor to provide an effective contact.The yielding or deformation of the ribs 21 and 36 precludes anyexcessive pressure developing on the conductor 43.

The same advantageous result is obtained in that the deformation of theribs 21 and 36 in the recess 16 and on the tab 31 enables the effectiveconnection of any conductor 43 within a wide range of sizes.

Because grooves are placed along the bottom of recess 16 and up each ofthe arms 13, the arms 13 bend toward each other at the bottom of recess16 and thereby preclude any bulging in this area.

If a compound or paste (not shown) is utilized in this portion of theconnector body 11, such compound would be retained in the grooves 22 and37 by the ribs 21 and 36 even upon endwise insertion of the conductor43. Upon compressive action, the compound would beforced against theconductor $3 for more effective usage.

With the particular construction of tabs 23 and 31 and their structuralrelationship with the width of recess and 16 respectively, the tabs 23and 31 will enter the recesses 15 and 16 within the oppositely relatedarms 12 and 13 in an alignment such that the ridges or serrations on themating portion of the arms 12 and 13 will interlock with thecomplementary ridges or serrations on the mating edge of the tabs 23 and31 respectively as the connector is compressed with the conductors 41and 43 in place.

A second embodiment of thecompressible electrical connector isillustrated in FIG. 6. In this embodiment, the mating portion of arm 12is provided with ridges or serrations 44. The mating edge of tab 23 isflat initially. Under compression, when a conductor is in place ingroove 15, the ridges or serrations 44 on the mating portion of arm 12will interlock with the flatmating edge of tab 23 by means of cold flowof metal into the ridges or serrations 44. The compressive force of thecompression tool will cause a mechanical interference to be created asthe smooth metal surface of tab 23 is deformed into the ridged orserrated mating portion of arm 12. This interlocking action will be veryeffective for connectors constructed of a soft, malleable metal whichwill accommodate the above mentioned cold flow of metal.

Similarly, in FIG. 6, the mating portion of arm 13 is provided withridges or serrations 45 and the mating edge of tab 31 is flat. Thecompressive force of the compression tool when the mating edge of tab 31is brought into contact with the mating portion of arm 13 will cause acold flow of metal into the ridges or serrations 45. The mechanicalinterference thus created will cause the connector to be interlocked.

FIGS. 7A, 7B, and 7C illustrate a modified construction of a tab 51 anda mating portion of an arm 52 that can be utilized the teeth engage eachother to lock the tab in the closed posi- In FIG. 7A, the tab 51 isshown in the open" position.

Upon compression, (FIGS. 7B and 7C), when a conductor (not shown) is inplace in the connector, the surfaces 53 and 55 easily slide over eachother. Thus, a positive interlocking is achieved between the teeth 54 atthe end of the camlike inclined surfaces 53 and the ratchetlike lockingteeth 55. This embodiment has the advantage of preventing prematurebinding or locking responsive to interference between the interlockingedges of the tab and the mating portion of the arm. This feature tendsto preclude any possibility that the sidewalls will either collapseafter a conductor has been compressively interlocked in the connector,or fail to make a completely tight, low resistance electricalconnection.

1 FIGS. 8A, 8B and 8C illustrate another modified construction of a tab57 and a mating portion of an arm 58. Again, to orient the reader, adot-dashed line 8A has been drawn in FIG. 6 to identify where thefragment of FIG. 8A may be located. This modified embodiment can beutilized advantageously in any of the embodiments of FIGS. 1, 6 and 7.As shown in FIG. 8A, the mating edge of the tab 57 is initially flat.The mating portion of arm 58 is provided with ratchetlike teeth 59.Again,

free of bindingat the interfacing surfaces.

For convenience in description, the term interlocking teeth willhereinafter be employed in the claims to generically denote all of theaforementioned means for establishing mechanical interference.

While the principles of the invention have been described above inconnection with specific apparatus and applications, it is to beunderstood that this description is made only by way of example and notas a limitation on the scope of the invention.

We claim:

1. A compressible electrical connector having integral enclosure tabswhich lock in place comprising: a connector body of malleable metalhaving a substantially l-l-shape in cross section to provide two pairsof upstanding arms, the arms of each pair being spaced-apart to providea recess for receiving a conductor, the recesses being open along theirlengths at opposed portions of the body, one of the arms of each pairincludingan integral tab bendable over the associated recess, the lengthof each tab being less than the width of the associated recess betweenthe pair of arms to assure entry of the tab into the recess, and whereinthe means for establishing mechanical interference interlocking teeth ona mating portion of the arm which interlock with a mating edge of thetab as the connector is compressed, said interlock providing anelectrically and mechanically secure joinder of said tab with said armwhen the tab is in a closed and compressed state enfolding and grippingthe conductor disposed in the recess.

2. The connector of claim 1 including complementary interlocking teethon said mating portion of said arm and on said mating edge of said tab.

3. The connector of claim 1 including a flat mating edge on said tab andinterlocking teeth on said mating portion of said arm.

4. A compressible electrical connector having integral enclosure tabswhich lock in place comprising: a connector body of malleable metalhaving a substantially I-I-shape in cross section to provide two pairsof upstanding arms, the arms of each pair being spaced-apart to providea recess for receiving a conductor, the recesses being open along theirlengths at opposed portions of the body, one of the arms of each pairincluding an integral tab bendable over the associated recess, thelength of each tab being less than the width of the associated recessbetween the pair of arms to assure entry of the tab into the recess, andinterlocking teeth on a mating edge of the tab which interlock with amating portion of the arm as the connector is compressed, said interlockproviding an electrically and mechanically secure joinder of said tabwith said arm when the tab is in a closed and compressed state enfoldingand gripping the conductor disposed in the recess.

5. The connector of claim 4 including a flat mating portion on said armand interlocking teeth on said mating edge of said tab.

